The present invention relates to a deep fryer comprising an oil tank, a movable basket intended to receive the product to be fried, an immersed heater controlled by a thermostat which turns the heater off when the oil reaches a given temperature, and means for reducing the drop in temperature which is due to the response time of the thermostat upon the immersion of the basket.
The heater may be an electric heater or a gas heater. The different foods which can be fried in such deep fryers must be fried at suitable temperatures which differ from one food to another. The operator selects the proper temperature on the dial of the thermostat and this thermostat is entrusted with maintaining the oil at this temperature by connecting and disconnecting the circuit of the heater. A signal light connected in parallel with the heater makes it possible for the user to know when the desired temperature has been reached. As soon as the thermostat disconnects the heater, the signal light goes out and the user can then immerse the basket containing the foods to be fried into the oil.
Today, greater and greater use is being made of frozen foods, such as fried potatoes, croquettes, fish, chicken legs, etc. They are immersed in hot oil while they are still frozen, that is to say at a temperature of from -17.degree. C. to -25.degree. C. This immersion results in a sudden large drop in the temperature of the oil. This drop is all the greater since the response time of the capillary thermostats used in practically all deep fryers is about 30 to 40 seconds. It has already been proposed to limit this drop in temperature by providing the fryer with an auxiliary time switch (U.S. Pat. No. 3,894,483) which is turned on simultaneously with the placing in operation of the basket immersion means and neutralizes the thermostat by starting the heating. The thermostat then takes over from the auxiliary time switch. The drop in temperature is thus reduced and a saving of time and energy is obtained.